Water tanks are often employed to provide users with heated water. Heated water is drawn from a water tank and usually dispensed from a tap, showerhead, or like device. Alternatively, the heated water may be for other uses such as a heated pool. The water tank normally receives unheated water from a water source, such as a mains water pipe. The water tank typically includes a controller having a user interface that allows a user to set a desired temperature for the water being held by the tank. If the tank's water temperature falls below the desired temperature, then the controller activates a heating element for warming the tank's water. When activated, the heating element begins to heat the water within the tank, and the heating element continues to heat the water until the water's temperature reaches or exceeds the desired temperature. In other arrangements, the controller is a simple thermostat such a bi-metallic strip type thermostat.
Activation of the heating element requires electrical power. In this regard, a heating element is normally comprised of one or more resistive elements that emit heat when electrical current is passed through the heating element. As a result, the operational costs associated with a water heater are directly related to the amount of heat generated by the heating element. More specifically, any increase in the amount of heat generated by the heating element normally increases the energy costs and, therefore, the overall operational costs associated with the water heater.
In some situations, the heating element is simply energised when the temperature of the water is below the thermostat. However, depending factors such as the time of day and the particular source of power, simply energising the heating element may cause undue power consumption.
It is an object of the present invention to provide a way of controlling the temperature of heated water which improves or at least ameliorates some of the abovementioned disadvantage or which at least provides the public with a useful choice. Other objects of the invention may become apparent from the following description which is given by way of example only.
In this specification, where reference has been made to external sources of information, including patent specifications and other documents, this is generally for the purpose of providing a context for discussing the features of the present invention. Unless stated otherwise, reference to such sources of information is not to be construed, in any jurisdiction, as an admission that such sources of information are prior art or form part of the common general knowledge in the art.